The present disclosure relates to toner cases that contain toner and image forming apparatuses that include the toner case.
In developing processing by an electrophotographic image forming apparatus, toner is supplied from a developing unit to an electrostatic latent image formed on the surface of a photosensitive drum or the like. A toner case, such as a toner container or an intermediate hopper, is used to supply toner to the developing unit.
An example of a toner case includes a case body that contains toner, a conveying member, which is rotatably attached to the case body, and an agitating member, which is rotatably attached to the case body together with the conveying member. With this toner case, a coupling is attached to one end of the conveying member. To rotate the conveying member, a rotational driving force is transmitted from a driving motor to the coupling. At the one end of the conveying member, a conveying gear is provided, adjacent to the coupling. The conveying gear engages an agitating gear having a large diameter, which is positioned at one end of the agitating member. Therefore, when the conveying member is rotated, the agitating member is also rotated.
Since the above toner case uses an agitating gear having a large diameter, however, there are restrictions on the location and size of the filling port through which toner is supplied to the case body. When a metal mold is used to manufacture the conveying member, only the coupling is typically molded by using a separate insert. With the above toner case, however, the coupling and conveying gear are adjacent to each other, so a portion of the metal mold, where the conveying gear is molded, may be scratched when the insert used to mold the coupling is replaced.
Another type of toner case is designed so that most of the conveying member is located in the case body. With this type of toner case, a large load may be applied to the conveying member due to, for example, the weight of toner supplied to the case body or a shock caused when the toner case drops. If the conveying member is structured by linking a plurality of members to improve ease of assembling or for another purpose, the above load is exerted on linked portions of the plurality of members, possibly damaging the linked portion.